"It's a little uneasy and unsure, but at the same time, exciting, because you know there are opportunities out there. I'd love to stay here, but part of me says, 'Well, there's nothing been on the table quite yet.' I'm remaining optimistic."

Bush has put together his two most productive seasons as a running back with the Dolphins. He rushed for a career-high 1,086 yards, made 43 receptions and scored seven touchdowns in 2011. He has 791 rushing yards, 29 catches and five touchdowns in 2012.

Bush hasn't been anywhere near the NFL leader in rushing yards, as was his 2012 goal, but he's the Dolphins' best running back, a locker-room leader and a player who's still one of the most versatile in the NFL. Still, the Dolphins don't seem eager to bring him back.

"It comes down to who needs me, who wants me, and, obviously, money," Bush said. "I want to play another five years. I think 12 years, as a running back, that's a good place to start."

The Dolphins' decision to move on from Bush wouldn't be shocking. He always has been better in a supporting role than a lead every-down back. And money could be an issue. But Daniel Thomas and Lamar Miller would be downgrades for the Dolphins.